Table 1 Selected conditions for oxidative rearrangement of THC 1a

From: Green oxidation of indoles using halide catalysis

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Entry

Oxidant (1.2 eq)

MX (5 mol%)

Solvents (v/v, 10/1)

Conv. (%)

Yield (%)a

1

Oxone

KBr

THF/H2O (1/1→10/1)

100

87–93

2

Oxone

KBr

MeCN/H2O (1/1→10/1)

100

84–93

3

Oxone

TBAB

MeCN/H2O

100

89

4

Oxone

TBAI

MeCN/H2O

55

33

5

Oxone

TBAC

MeCN/H2O

40

19

6

Oxone

KI

MeCN/H2O

64

37

7

Oxone

KCl

MeCN/H2O

28

19

8

Oxone

NH4Cl

MeCN/H2O

30

17

9

Oxone

NaCl

MeCN/H2O

32

16

10

Oxone

–

MeCN/H2O

20

0

11

H2O2

KBr

MeCN/H2O

<10

0

12

K2S2O8

KBr

MeCN/H2O

25

12

13

NaClO

KBr

MeCN/H2O

75

54

14

NaClO2

KBr

MeCN/H2O

<10

0

15

t-BuOOH

KBr

MeCN/H2O

<10

0

  1. ayield was obtained by 1H-NMR analysis of the crude product using CH2Br2 as the internal reference. TBAB: tetrabutylammonium bromide; TBAC: tetrabutylammonium chloride; TBAI: tetrabutylammonium iodide
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